Polyteny: A Source of Cryptic Speciation among Copepods

Abstract

A large form of the copepod Pseudocalanus is found in two warm, semi-landlocked fiords in arctic Canada, together with a similar but smaller form attributable to the widespread P. minutus. The large form has the same chromosomne number as P. minutus, but has larger chromosomes and a higher nuclear DNA content. There are suggestions in the literature that other similar polytenic and cryptic species occur among copepods.